University of Wisconsin - Extension

As the long, cold, mostly snowless winter of 2003 came to an end, many Wisconsin farmers worried that weather conditions could have caused severe winterkill damage to their alfalfa fields.

Forage specialists at the University of Wisconsin-Extension worried, too, and in March they advised farmers to inventory their feed supplies to make sure they would have enough to get their herds through the early summer. They also began developing a series of fact sheets with management advice for farmers who might have lost alfalfa stands. These fact sheets are currently available on the UW-Extension Team Forage website at http://www.uwex.edu/ces/crops/uwforage/FocusonForage.htm .

By late April, it appeared that winterkill would not be as severe and widespread as some people feared, but UW-Extension forage specialist Dennis Cosgrove at UW-River Falls, says there are areas where alfalfa stands were killed or badly injured.

�Winterkill reports are few in the southeastern part of the state. Most of the damage reports come from north of a line between Prairie du Chien and Manitowoc,� he said. From these early, spotty reports, Cosgrove said it appears that alfalfa stands with new seedlings or plants less than two years old were least likely to have been damaged. Stands that were last cut in the fall were most likely to have been damaged.

�In some places, injured plants started greening up and growing, but then died. In some other areas, late cold temperatures may have killed buds that had broken dormancy. There also appears to be some heaving on heavy soils as plants are broken off deep in the soil,� Cosgrove explained

�Obviously, the cold temperatures took a greater toll than we originally thought. �

Cosgrove said plants that appear gray and water soaked or show stringy, dessicated roots are dead. If roots are still white and turgid there is a good chance they will recover but they may be slow to green up and may produce reduced yields.

Cosgrove expects to hear reports of more damaged alfalfa stands in the next few weeks and urged farmers to get out to inspect their alfalfa fields now to assess how much, if any, damage has occurred.

Cosgrove said he also has received reports of winterkilled orchardgrass and perennial ryegrass.

UW-Extension Team Forage �Focus on Forage� fact sheets of interest to farmers with winterkilled alfalfa stand include the following titles:

• Making a Feed Inventory

• Feeding Strategies When Alfalfa Supplies are Short
• Paying for Unexpected Feed Expenses

• Seeding Alfalfa Fields Back Into Alfalfa

• Sorghums, Sudangrasses, and Sorghum-Sudan Hybrids

• Forage Options Following Alfalfa Winterkill

• Pea and Small Grain Mixtures

• Evaluating and Managing Alfalfa Stands for Winter Survival

• Seeding into an Existing Alfalfa Stand

• Cereal Forages for Spring Seeding

• Planting Corn for Silage After a First-Cut Alfalfa Harvest

All are available on the Team Forage website, http://www.uwex.edu/ces/crops/uwforage/FocusonForage.htm .

Another source of information is UW-Extension publication number A3620 �Alfalfa Stand Assessment,� which is available through your county UW-Extension office.